class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int>>& ob) {
        int m = ob.size(), n = ob[0].size();

        vector<vector<int>> dp(m + 1, vector<int>(n + 1));
        dp[1][0] = 1;

        for (int i = 1;i < m + 1;++i)
        {
            for (int j = 1;j < n + 1;++j)
            {
                if (ob[i - 1][j - 1] == 1)
                {
                    dp[i][j] = 0;
                    continue;
                }
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
            }
        }

        return dp[m][n];

    }
};